Present address: Faculty of Life Sciences, University of Manchester, Jacksons Mill, PO Box 88, Sackville Street, Manchester, M60 1QD, UK. Tel.: + 44 161 3064225; E-mail: Robert.Nudds@manchester.ac.uk
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A shortening of the manus precedes the attenuation of other wing-bone elements in the evolution of flightlessness in birds
Article first published online: 17 FEB 2009
DOI: 10.1111/j.1463-6395.2009.00391.x
© 2009 The Authors. Journal compilation © 2009 The Royal Swedish Academy of Sciences
Additional Information
How to Cite
Nudds, R. L. and Davidson, J. S. (2010), A shortening of the manus precedes the attenuation of other wing-bone elements in the evolution of flightlessness in birds. Acta Zoologica, 91: 115–122. doi: 10.1111/j.1463-6395.2009.00391.x
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Present address: Faculty of Life Sciences, University of Manchester, Jacksons Mill, PO Box 88, Sackville Street, Manchester, M60 1QD, UK. Tel.: + 44 161 3064225; E-mail: Robert.Nudds@manchester.ac.uk
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Present address: Department of Zoology, Stockholm University, 106 91 Stockholm, Sweden. E-mail: jessica.slove.davidson@zoologi.su.se
Publication History
- Issue published online: 20 DEC 2009
- Article first published online: 17 FEB 2009
- Accepted for publication: 26 November 2008
- Abstract
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Keywords:
- bird;
- comparative analysis by independent contrasts (CAIC);
- comparative analysis;
- flight;
- wing length;
- wing skeleton
Abstract
Nudds, R. L. and Slove Davidson, J. 2010. A shortening of the manus precedes the attenuation of other wing-bone elements in the evolution of flightlessness in birds. —Acta Zoologica (Stockholm) 91: 115–122
This is the first study to present evidence for a general pattern of wing-bone attenuation during the early stages of the evolution of flightlessness. A comparative analysis using phylogenetic independent contrasts showed that in families that contain both flighted (volant) and flightless species, the volant species have shorter wings and total-arm (humerus + ulna + manus) lengths relative to their body masses than the species within their wholly volant sister families. A shortening of the manus may typify the early stages of the evolution of flightlessness, with the humerus and ulna attenuating later, perhaps because of their role in maintaining the position of the aerodynamically important alula. A shorter wing relative to body mass was not the result of the inverse (i.e. heavier body mass relative to wing length) because mean body masses of volant members of flightless families were similar to or lower than those of their wholly volant sister families. Despite finding a common trend in the wing morphologies of volant members of flightless families, it seems unlikely that a general model of selection pressures driving the evolution of flightlessness exists. At the very least, a dichotomy between those birds that have lost the ability to fly in order to gain the ability to swim and terrestrial forms, may persist.